


Oh, Boy!

by kuroneko_06



Category: Haikyuu!!
Genre: Child AU, M/M, Possessive Tsukishima Kei, Tsukiyama - Freeform, older!tsukishima, younger!yamaguchi
Language: English
Status: Completed
Published: 2017-05-16
Updated: 2017-05-16
Packaged: 2018-11-01 01:06:41
Rating: Teen And Up Audiences
Warnings: Underage
Chapters: 1
Words: 1,665
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10911165
Author URL: https://archiveofourown.org/users/kuroneko_06/pseuds/kuroneko_06
Summary: [child au] Tsukishima Kei is not a shotacon. He just seriously and hopelessly likes Yamaguchi.





	Oh, Boy!

**Author's Note:**

> I have a thing for Tsukishima being smitten with a younger Yamaguchi.  
> a sort of sequel to **Oh, Baby!**

Tsukishima was eleven when he met six-year old Yamaguchi and considered the possibility of himself being a shotacon. 

He was twelve when he realized that his masked adoration and fondness for the boy doesn't have anything to do with his age. After all, he still finds other kids annoying and whiny. And even if there are kids who are cuter or prettier or lesser of a crybaby, he still thinks Yamaguchi is way better. Yamaguchi may be timid, clingy, and clumsy; but, he's also pure-hearted, smart, and definitely has the most beautiful smile Tsukishima has ever seen. It was also during this age when Tsukishima realized that he's a total sap. But yeah, he's not a shotacon. He just seriously and hopelessly likes Yamaguchi.

Tsukishima was thirteen when he realized that it may have been for the best that Yamaguchi was younger than him. After all, having his Tadashi wait for him to get home from school almost everyday, going "Welcome back, Tsukki!" is adorable. Having Tadashi sit on his lap while doing homework or watching tv is always enjoyable. And the kisses on the cheek he routinely gives Kei whenever he walks the adorable brunette home is quite the advantage, too.

He was fourteen when his possessive side hit him like a truck. Yamaguchi's nine and was getting impossibly cuter by the day. Unfortunately, others were also realizing that fact. The bullying has stopped and Yamaguchi has even made some friends encouraging him to join the volleyball club. 

"This is all thanks to you, Tsukki!" or so Yamaguchi says.

It's fine that his Tadashi is developing a love for the sport that Kei himself taught him, and that his Tadashi is gaining more confidence in himself. What's not fine is that Yamaguchi has started going on sleepovers on houses that's not Tsukishima's and that his teammates are calling him "Tadashi". How it made Tsukishima's blood boil.

Fortunately, Yamaguchi still thinks that Tsukishima is the greatest person in the entire planet. Meaning, he still always listens to whatever Kei tells him. Thus, making it easier for Tsukishima to manipulate him into thinking no other sleepovers would be as fun as with Tsukishima and that it's not cool having lots of people call you by your given name. 

\--------

Yamaguchi was six when he met Tsukishima, the coolest person he has ever met. Most definitely!

He was seven when he realized that Tsukishima is probably the bestest friend he can ever have and that he wants to be the always-calm-and-collected blonde's best friend, too. 

And so, Yamaguchi gathered his courage. "T-tsukki-nii? Can I ask you something?"

"Hm?" The older boy replied as he stroked Yamaguchi's ahoge. 

"Will.. will you be my best.. friend..?" He shyly peered at the older boy cradling him.

Tsukishima was taking quite a while to respond that Yamaguchi began blushing and worrying that his Tsukki-nii wouldn't like a scrawny kid like him to be his best friend. He was trying his best not to burst crying. He was about to stand up and tell Tsukki-nii to forget it when he finally responded.

"On one condition."

"What condition?" Yamaguchi excitedly asked. He'll agree to whatever his Tsukki-nii asks of him just as long as they'll be best friends.

"From now on, you can no longer call me 'Tsukki-nii'." 

Yamaguchi was certainly not expecting that. "But, why?" He unconsciously tilted his head to the side as he asked. 

Tsukishima hugged him tighter. "Because best friends are equals. So, it doesn't matter that I'm older or that you're younger."

Yamaguchi's eyes sparkled with awe. "Oh! Then, then is it fine if I call you just 'Tsukki'?"

"Yup." then, Tsukki went back to stroking his ahoge. 

And so, they became even more closer and tighter than before--inseparable best of friends.

Yamaguchi was eight when he began having sleepovers at Tsukki's every other weekend. It was also during this age that Tsukki began teaching him how to play volleyball. Tadashi's really lucky to have Tsukishima Kei as his best friend. The handsome, blonde boy is always so kind and patient with him. How he wishes he can do more than to kiss Tsukki on the cheek and give him hand-made cards to show his gratitude. But Tsukki always says that those are more than enough for now. That he can think of something else to give him when he is older. Tsukki's really the bestest. 

Tadashi was nine when his mother told him that he shouldn't cling to Tsukishima so much and abuse the older boy's kindness. It made Yamaguchi worried. He doesn't want his Tsukki to get fed up with him. Fortunately, learning volleyball made him less clumsy and helped him gain friends his age. And so, he decided to join the volleyball club to keep himself a bit more busy and a lot less clingy. 

It was really fun at first. His teammates even invited him for sleepovers during weekends. But it wasn't the same. He misses Tsukki giving him fries whenever the older boy comes home even just twenty minutes late for their sleepover weekends. Sure it's always already soggy by the time Tsukki arrives, but it's the thought that counts. And actually, Yamaguchi's starting to prefer soggy fries over crispy ones. He also misses Tsukki stroking his hair as they watch documentaries or movies. He misses Tsukki hugging him to sleep, too. He most especially misses Tsukki himself! 

It's really different spending time with your best friend, after all. 

And so, after three months, Yamaguchi's finally had enough and gradually fell back into the habit of "clinging to Tsukki so much" and sleeping-over at his house every other weekend. Fortunately, his friends understood that he needs the time he spends with the older teen like he needs to drink lots of water after every training. They even agreed when Yamaguchi asked them to stop calling him with his given name because Tsukki told him it's not cool having almost everyone use your given name. Some of them even wished they have a cool, older best friend like he does. Tadashi made it clear that he won't share his Tsukki with them, though. 

\--------

Tsukishima Kei was fifteen when he realized that Yamaguchi Tadashi may be the coolest and smoothest ten year-old he's ever known. Scratch that, Tadashi definitely is! 

It was the first time that Kei will be the one sleeping-over at Tadashi's and Kei just finished laying out the futon in which Tadashi would be sleeping in with him, when...

"Tsukki?" 

"Hm?"

"Will... will you marry me?" 

And as a blue plastic ring from the pretty brown-haired boy's pocket was being shoved in his face, Kei almost spit his heart out. "What?!"

"Y-you don't want to?" Yamaguchi looks about ready to cry. 

OF COURSE I DO! Tsukishima almost uncharacteristically screamed. 'Okay, Kei.' He inwardly said, 'Compose yourself. Act natural.' "Well, this is just so sudden. What even brought this about?"

"You know how I attended a wedding with 'kaasan last weekend? I got curious and asked her why people get married... and she said that people get married because they love one another so much and want to spend forever with each other and... and I love Tsukki so, so much and I would really, really like to spend forever with you. So... will you marry me?" He looked at Tsukishima expectantly.

This boy will seriously be the death of Tsukishima Kei. Here he is trying his best to be above his raging teenage hormones and yet here Tadashi is saying things that makes Kei want to elope with him somewhere far, far away. Just the two of them. That would be very nice, right? "NO, NO, NO." Tsukishima did not realize he said that aloud.

Yamaguchi has never looked so dejected in all of the years they spent together. Tsukishima, on impulse, reached out and hugged him soothingly. 

"D-do you.. do you not love me back, Tsukki?" Kei thinks he just saw the gates of hell open for him for making Tadashi feel so heartbroken.

"Of course not! I do love you! You know that, right?!" Unsurprisingly, Yamaguchi Tadashi is the only one who can make Kei panic and lose his cool like this.

"Then why? Is it because you're cool and I'm not?"

"Coolness doesn't really have anything to do with marriage, you know?"

"But you do think I'm uncool? You didn't deny it, after all!" Yamaguchi pouted.

"Shut up, Tadashi."

"Sorry, Tsukki."

"Listen," Tsukki sighed, "getting married is not that simple. You need to be dating first." 

"Then let's go dating!" Yamaguchi beamed. 

"You have no idea what a date is, do you?"

"Nope. What is a date, Tsukki?"

"Well.. doing stuff to get to know each other better..? Going on parks... eating together... watching movies together... holding hands... whatever fun stuff you want to do together, I guess." Kei tried to answer as casual as possible.

"Then, doesn't that mean we've been going on dates since forever?" Tsukishima tried his best not to smile too much. He never expected he'd be this elated to have Tadashi technically acknowledge them as already dating. "then why can't we get married?"

"Because we both have to be of legal age first." and our laws won't allow us to get married so I have to study hard, graduate, and get a job that would pay me shitloads of money so we can go to a country that will allow us to get married.

"Oh." Yamaguchi finally understood. "Then, when I turn 18 I'll just ask you again to marry me!" 

Seriously, this boy kills and brings him back to life every time.

"No, don't."

"Eeeeeh~ why not, Tsukki?!" Yamaguchi whined.

"You don't have to. Because by then, I would be the one to ask you to marry me."

\--------

Yamaguchi Tadashi was eighteen and had just graduated from high school when his childhood best friend and boyfriend, Tsukishima Kei, twenty-three, asked him to marry him. 

 

And Tadashi, of course, said yes to his Tsukki.


End file.
